Process of separating suspended matter from liquids containing mineral value.



UNITED sTA Es PATENT oFFioE.

PROSPER JEAN AUG-USTE IIIAIG-NEN, OF PHILADELPHIA, PENNSYLVANIA.

PROCESS OF SEPARATING- No Drawing.

MATTER FROM LIQUIDS CONTAINING MINERAL VALUE.

I Specification of Letters Patent. Patented Aug. 31, 1909. Applicationfiled October 5, 1908.

Serial Nd. 456,135.

To all whom it may concern: a l 7 Be it known that I, PROSPER JEANAUeUs'rE MAIGNEN, of Philadelphia, in the State of Pennsylvania, haveinvented a certain new and useful Improvement in Processes of SeparatingSuspended Matterfrom Liquids Containing Mineral Value, whereof thefollowing is a specification.

My improvement is particularly applicable to solutions of cyanid whichhave been employed for extracting values from metalvlie ores, and forthe purpose of separating the spent slime from such enriched solutions.

Originally such separation was effected by allowing the mixture of slimeand solution to settle for a considerable period of time;

the supernatant liquid, being decanted or drawn olf when consideredclear enough.

However, the particles of suspended matter are so small, andtheir'hydraullc value, 71. e.

the velocity at which they settle, in still water, is so low, that it isfrequently the case that not more than 50% of the supernatant solutionis clearenough for decantation after the solution has been allowed tosettle for forty-eight hours. Therefore, inorder to recover the metallicvalues that are :left' in the portion of the solutionwhich' is not clearenough for decantation, it is necessary to add fresh water, allow more.time for settling, and again remove suchportion of the supernatantsolution as is clear enough for decantation. j Thecycle of operationsaforesaid,necessary to effect the clarification and recovery of thedissolved values in this manner, must ordinarily be repeated from fourto-twelye times, and may require fifteen days or. more for itscompletion. Even then the decanted solution is not clear enough to besent to the precipitation boxes without filtration. Various attemptshave been made to accelerate the sedimentation of the slimes from' icalswhich have been tried, and the.eflects.

thereof, may be noted as follows :'Caustic potash, sulfuric acid, andalum, which after forty-eight hours settling of the solution renderrespectively 40%, 87%, and 39% of the supernatant solution clear enoughfor acid to the enriched solution consumes cyanid, decomposes thesolution, and forms the dangeroushydro-cyanic acid.

It is the-object of my invention to effect the rapid separation of slimefrom solutions which have been enriched by metallic ore values, and toeffect such separation solely by sedimentation, and in practice it isfound that the process herein described, effects complete. sedimentationand clarification of a cyanid: solution in less than half an hour, andwithout any modification of such solution which would in any wiseinterfere with its subsequent em loyment in accordance with the practiceof the art.

My process consists in adding simultaneously to the slimy-solution, anacid salt and an alkaline salt, of such character and pro-- rapid andcomplete, that no harm can be done to the metallic values of thesolution, even if a considerable excess of said salts is employed. Thisfeature of the process is very important because whatever quantity isfound necessary to produce a rapid and perfect clarification. of thesolution, may be used without injury to the dissolved values. Thecoagulation resulting from my process is analogous to that produced bythe addi- 5 the fine particles of suspended matter so thatv as saidnetwork of flakes sinks to the bottom of the solution, it-, carrieswith'it the-sue pendedmatter and leaves the supernatant solution clear;In the practice of my process,

it is found that all of the particles of slime suspended in the solutionare precipitated in less. than twenty-minutes, although a few minuteslonger may be required for the sub- 1dence of .some-ofthe flakes whichhave le doneno, workinseparating the particles of ore. The final; resultof my process is a perfectly clear solution which has lost none of itsmetallic values.

then the reagents aforesaid, aluminum' 2o--:sulfate and sodiumcarbonate, are used in their commercial powdered form, they may be addedseparately, simultaneously to the solution or. mixture to be clarified,or they .may be mixed together and added as one mixed powder; In thelatter case, when the mixed powder is; to be kept for any considenable.time. before being used, I find it desirable toaddthereto some, moreorless inert,'po,wdered substancecapable of preventswing-prematurereaction between the acid and alkalinev salts.

It. isto be understood that. the respective acid-and alkaline salts tobe employed, which are tobe mixed inithe solutionto be clarif fi%d,11n&y.b6 separately dissolved and added I thelfetoimseparate streams, at thesame time' It: is to beunderstood that said two salts may be mixed asabove described'in equivalent roportions, if it. is desired that theyshall 40j'not modify the acidity -oralkalinity of they I solutiomtowhich they are added. On the otherhand, thessolution may be modified ins thisirespeot if desired, by employing a relatively excessive amount ofone or the other of said salts.

' The improved process above described, is advantageous in economy ofwater, time,

tank room, and the avoidance of waste; the

process as applied to the clarification of a cyanid solution, it is tobe understood that it is applicable vto the concentration and recoveringof the fine flour and flake gold of placer mines.

I do not desireto limit myself to the precise details of procedure abovespecified, as it is obvious that various modifications may be madetherein without departing from the essential features of my invention asdefined inthe appended claims.

I claim 1. The process of separating suspended matter from a liquidcontaining mineral value, which consists in adding to said liquid sodiumcarbonate and aluminum sulfate in such proportions as not tosubstantially affect the degree of alkalinity of said liquid. Theprocess of separating suspended matter from a liquid containing mineralvalue, which consistsin adding to said liquid sodium carbonateandaluminum sulfate in a liquid state, in such proportions as not tosubstantially aifectthe degree of alkalinity of said liquid.

In testimony whereof I have hereunto signedmy name at Philadelphia,Pennsylvania, this thirtiethday of September 1908.

H V raosrrr. JEAN AUGUS'IE MAIGNEN. Witnesses:

' 'ARTHUR E. PAIGE,

CAsPnRS. BUTCHER.

